Vice President Biden gestures during a meeting with Chinese Vice President Li Yuanchao after a welcoming ceremony at the Great Hall of the People in Beijing on Dec. 4. / Lintao Zhang, AFP/Getty Images

by Calum MacLeod, USA TODAY

by Calum MacLeod, USA TODAY

BEIJING - Vice President Biden flew to Seoul on Thursday to talk about Asian security with South Korean leaders worried by Beijing's aggressive claim that it now controls all airspace over the vast East China Sea.

Biden received no concessions a day earlier from China on its new air defense zone that has the region on edge.

In Beijing on Thursday morning, Biden told American business leaders he had been ''very direct'' with President Xi Jinping about the U.S. government's objections to a zone that has also angered Japan.

"China's recent and sudden announcement of a new air defense identification zone has, to state the obvious, caused significant apprehension in the region,'' Biden said.

But as China's economy grows, its stake in regional security also rises, he said.

"The current tension in the East China Sea is stirred up by Japan to win pity," said an editorial in the Global Times, a Communist Party-controlled newspaper.

Chinese analysts have said the new air zone is primarily aimed at forcing Japan to begin negotiations over a group of uninhabited islands annexed by Japan in the 19th century.

Japan, South Korea and Taiwan are located along the East China Sea as is the eastern coast of China. The sea contains vast fishing resources and is estimated to have untapped oil and natural gas deposits, as well. China says it all belongs to it.

On Thursday, Biden touched down on a U.S. military base south of Seoul to meet with South Korean President Park Geun Hye. He is to give a speech Friday at Yonsei University about America's Asia policy and the U.S.-Korea relationship.

Biden will also lay a wreath at a ceremony honoring fallen U.S. troops and visit the Demilitarized Zone between South Korea and North Korea.

Biden's Asia trip was supposed to be largely about improving trade ties. But the first leg in Japan was dominated by the news that China said it was creating an air defense zone over the entire sea and all foreign military and commercial aircraft must notify its government if they wish to pass through.

The air defense zone covers some areas of ocean that are far closer to Japan, Taiwan and South Korea, and it includes waters considered international by the United States. The zone also covers the Senkaku Islands, annexed by Japan and purchased from a private landowner.

Many nations, including the United States, have set up air defense zones that extend from their shorelines to protect against enemy aircraft. China's zone is extraordinary in its massive outward extension. And other zones do not require notification if aircraft are merely passing through and not landing in the country.

Japanese Prime Minister Shinzo Abe had hoped the United States would not kowtow to China on the matter, according to the news media in Japan. Abe demanded that China reverse itself on the air zone. Biden did not say whether he asked China to do so.

Biden did not say exactly what he discussed with Xi.

In his public remarks after the Biden meeting, Xi extolled the benefits of closer U.S.-China ties as he laid out "profound and complex changes" underway in Asia and across the globe.

"The world, as a whole, is not tranquil," Xi said.

Chinese and Japanese ships and planes have come into increasingly perilous proximity near the islands over the past year. China wants the United States to join it in pressuring Japan.

Sun Zhe, director of the Center for Sino-U.S. Relations at Qinghua University in Beijing, said the U.S. should reduce "provocative" actions such as flying B-52s through the zone, or risk turning China's dispute with Japan into a conflict between China and the U.S., he said.

The zone "is part of a continuous effort to push the USA and Japan back, as both conduct over 500 cases of reconnaissance close to China's borders," said Sun. "China is nervous and uncomfortable about this."